Process for refining and stabilizing fat-soluble vitamin-bearing materials



Patented Apr. 4, 1944 PROCESS FOR REFINING ANB STABKEfiEiW-G FAT-SOLUBLEVITAMIN-BEARHNG lfidflliii RIALS corporation of New Jersey No Drawing.Application June 13, Serial No. 398,594

11 Claims.

This invention relates to the refining and stabilization of fat-solublevitamin-containing materials, more particularly to the removal ofundesirable tastes and odors from fat-soluble vitcmin-containing oilsand concentrates, and to the stabilization of said vitamin-containingmaterials against oxidative changes.

As is well known, fish liver oils are an excellent source of bothvitamins A and D; moreover,'

saponiflcation oi. fish liver oils and extraction of the unsaponifiablematerial therefrom yields fatsoluble vitamin concentrates which havefound a wide variety of uses. While such products are eminentlysatisfactory for many purposes, they generallyvpossess theundesirabletaste and odor normally associated with products of fishorigin. Fat-soluble vitamin-containing materials derived from sourcesother than of a fish origin also may possess undesirable tastes andodors. Many attempts have been made in an endeavor to improve the tasteand odor of fat-soluble vitamincontaining materials objectionable inthese respects. For example, an alkali refining method has been employedfor improving the tastes and odors of vitamin oils: in this method analkali soap is prepared in the presence of the oil and then removed, thesoap tending to carry with it some of the objectionable taste and odor.However, this method possesses many disadvantages,

among them being that the oil becomes less stable when treated in thismanner; furthermore, the odor and taste of the oil are not improved asmuch as might be desired. Another method commonly employed for improvingthe taste and odor of vitamin oils and concentrates involves passing 1fat-soluble vitamin-containing materials having objectionable tastes andodors.

It is also the object of this invention to provide fat-solublevitamin-containing materials which have no undesirable tastes or odorsand are also relatively stable to oxidative changes.

In my copending application Serial No. 351,909, filed August 8, 1940, aprocess isdisclosed and claimed whereby the antioxidant principles of avegetable oil containing natural antioxidants may be concentrated manyfold by treating the oil with a solvent such as isopropanol at roomtemperature or at temperatures above room temperature, cooling themixture to a temperature within the range of 0 C. to -70 C., andseparating from the oil the isopropanol fraction which is immisciblewith the oil at the lower temperature. The major portion of theantioxidant principles of the original oil is concentrated in theresidue which remains on evaporation of the isopropanol from theisopropanol soluble fraction.

In my copending application Serial No. 307,547, filed June 11, 1941, aprocess is disclosed and claimed whereby the antioxidant principles ofan oil-bearing plant material containing natural antioxidants may beseparated from said mate rial and concentrated many fold by means of aprocess similar to that of my copending application Serial No. 351,909.

I have found that the undesirable taste and odors of fat-solublevitamin-bearing materials objectionable in these respects may besubstantially completely removed by heating such fat-solublevitamin-containing materials at a temperature between about C. and about200 C. with an antioxidant fraction prepared in accordance with theprocess of application Serial No. 351,-

909, as described hereinabove, from a vegetable oil containing naturalantioxidants, or with an antioxidant fraction prepared in accordancewith the process of application Serial No. 397,5'l7, as

described hereinabove, from an oil-bearing plant material containingnatural antioxidants.

In addition to removing the undesirable tastes and odors, thevitamin-containing material which is treated is also rendered morestable to oxidative changes. A fat-soluble vitamin-containing materialmay be treated in accordance with the process of my invention by mixingthe material with an antioxidant fraction prepared in accordance witheither of the processes referred to above, and heating the mixture at atemperature between about 60 C. and about 200 Cain an open vessel.Preferably, however, the mixture 'is heated at the desired temperatureunder a reduced pressure in an inert gas atmosphere in order to minimizedestruction of the vitamins and to assist in the removal of theodoriferous substances. It will be found in every case that theresulting products possess substantially no undesirable tastes or odorsand hence are eminentiy suitable for practically all purposes,particularly for human consumption; and more over, the vitamin potenciesof the materials refined are not materially affected by the refiningprocess. Also, the vitamin-bearing material is protected againstoxidative changes by the natural antioxidants which are added to saidmaterial by the addition of the antioxidant fraction.

Any fat-soluble vitamin-containing material having an undesirable tasteand odor may be treated in accordance with my invention; thus materialscontaining vitamins A, D, E or K, such as, for example, cod liver oil,halibut liver oil, sword fish liver oil, tuna liver oil, shark liveroil, whale liver oil, porpoise liver oil, seal liver oil and similaroils may be treated, as well as fatsoluble vitamin concentratesobtained, for example, by saponification of a vitamin-containing oil andextraction of the unsaponifiable material. The process of my inventionis particularly applicable to the refining of vitamin A and/or Dcontaining oils or vitamin A and/or D concentrates of fish origin, sincetreatment of such materials in accordance with my invention producesproducts far superior to any of those now on the market. Thevitamin-containing materials to be treated in accordance with myinvention should not contain any foreign metals, since the presence ofsuch metals usually accelerates deterioration of the vitamin A or Dcontent of the oil or concentrate at the elevated temperatures employed.

The materials from which the antioxidants which are used in the processof my invention are extracted in accordance with the process ofcopending application Serial No. 351,909 may be any fatty materialcontaining naturally-occurring antioxidants, or mixtures thereof;preferably crude materials containing such antioxidants are employed.The term fatty material is used herein to include oils, fats and waxescontaining fatty acid radicals. There are many such materials containingnatural antioxidants known to the art. Thus vegetable oils and fats,such as soybean oil, wheat bran oil, wheat germ oil, corn germ oil, cornoil, oat oil, rye oil, olive oil, sesame oil, cottonseed oil, palm oil,cocoa butter, palm kernel oil, coconut oil, rice oil, rice germ oil,linseed oil, oiticia oil, teaseed oil. perilla oil, alfalfa seed oil,celery seed oil, hemp seed oil, kapok oil, mustard seed oil, rape seedoil, poppy seed oil, sunflower seed oil, pumpkin seed oil, melon seedoil, peanut oil and the like may be treated.

Also one may prepare antioxidant fractions to be used in the process ofmy invention by treating an oil-bearing plant material'containingnatural antioxidants in accordance with the process of my copendingapplication Serial No. 397,547. For example, one may prepare fractionscontaining natural antioxidants by treating soybeans, wheat bran, wheatgerm, corn germ, corn grain, oats, rye, sesame seed, cotton seed, palmkernels, cocoa bean, copra, rice, rice germ, flax seed, hemp seed, teaseed, perilla seed, mustard seed, rape seed, poppy seed, sunflower seed,pumpkin seed, melon seed. peanuts, celery seed, alfalfa seed, tomatoseed, or any other oil-bearing. plant ma.- terial containing naturalantioxidants.

As set forth in the copending applications Serial Nos. 351,909 and397,547 above referred to, antioxidant fractions are obtained bycontacting vegetable oils or oil bearing plant material with a suitablesolvent such as ,isopropanol at temperatures above room temperature,separating the solvent from the material insoluble therein, andthereafter removing the extracted natural antioxidant concentrate fromthe solvent. As also set out in the patent applications above referredto, there may be employed instead of the isopropanol, any of thesolvents coming within the classe set forth in the table to follow:

TABLE 1. Aliphatic and alicyclic monohydroxy alcohols containing from 3to 6 carbon atoms.

2. Esters formed by the reaction of aliphatic and alicyclic alcoholswith aliphatic monocarboxylic acids, said esters containing not morethan 8 carbon atoms.

3. Aliphatic and alicyclic aldehydes containing not more than 6 carbonatoms.

4. Aliphatic ketones containing not more than 6 carbon atoms.

It will be noted that these preferred solvents are all liquid organiccompounds having the properties of being substantially miscible withfatty oils at temperatures substantially below room temperature;experiments in this connection have shown that solvents of this classmay be used generally in the process hereinabove described.

In carrying out the process of my invention a fat-solublevitamin-containing material having an objectionable taste and odor maybe mixed with a suitable amount of an antioxidant fraction and themixture heated to a temperature between about 60 C. and about 200 C. Theamount of antioxidant fraction to be used will depend upon theparticular antioxidant fraction employed and to some extent upon thetaste and odor of the vitamin-bearing material which is to be refined.Generally it may be said'that an amount of antioxidant fraction betweenabout 0.5% and about 10% of the weight of the vitamin-bearing materialmay suitably be used. The temperature at which the mixture is heated isparticularly important, since I have found that at temperatures belowabout 60 C. the undesirable taste and odor are not substantiallycompletely removed from the fat-soluble vitamin-containing material; andat temperatures above about 200 C. deterioration of the vitamins is aptto occur, particularly if a vitamin A-containing material is beingtreated. In most cases if the mixture is heated above about C. a slightdarkening of the oil is likely to occur which is possibly caused by thedecomposition of phosphatides that may be present in the antioxidantfraction. Oftentimes, this darkening is unobjectionable, and when suchis the case, I prefer to heat the mixture at a temperature between aboutC. and about C. However, when it is desired to obtain a deodorized,stabilized oil having substantially the same color as the original oil,I prefer to heat the mixture at a temperature between about 100 C. andabout 130 C. Usually the heating period required to obtain the desiredresults when the heating is carried out at the higher temperatures will.be shorter than when the heating is done at the lower temperatures.Just as eflicient results may be obtained, however, by heating themixture at temperatures even as low as about 60 0., provided the mixtureis heated for a somewhat longer period'of time. If it is desired to heatthe mixture at temperatures above about 130 C. without having the colorof the oil darkened to any material extent, the antioxidant fraction maybe treated to remove any phosphatides that may be present before thefraction is added to the oil which is to be treated. The phosphatidesmay be substantially completely removed from the antioxidant fraction bydissolving the fraction in acetone, cooling the acetone solution toabout --20 C. and removing the fraction insoluble at that temperature.When the oil is heated with an antioxidant fraction which has been sotreated, the color of the oil will remain substantially unchanged evenwhen the mixture is heated to temperatures as high as 200 C.

The heating may be conducted in an open vessel if desired; however, inorder to avoid the danger of deterioration of the vitamin A content ofthe materials treated in accordance with my invention, the heating stepis preferably carried out in the presence of an inert gas such asnitrogen or carbon dioxide. Furthermore, I have found it desirable toheat the mixture at reduced pressures, preferably at pressures belowabout 20 mm. since under these conditions removal of the odoriferousconstituents of the oil or concentrate is accelerated. The time ofheating may vary to some extent; generally between about two minutes andabout one hour, e. g. between about minutes and about minutes, issuilicient.

In some cases, as noted hereinabove, it may "be found that the processof my invention, while it substantially improves the odor and taste ofthe fat-soluble vitamin-containing materials, also imparts thereto acolor somewhat darker than that possessed by the original material. Thiscolor may be easily removed by contacting the refined vitamin-containingmaterial with a decolorizing agent such as decolorizing carbon, wherebya light-colored product substantially free from undesirable tastes andodors is obtained. If desired, the fat-soluble vitamin containingmaterials may be decolorized by contact with decolorizing carbon priorto the refining process of my invention. The decolorizing treatments arepreferably carried out by mixing the vitamincontaining material with adeaerated mixture of decolorizing carbon and a solvent for the materialand agitating the mass in the absence of air; this process is describedand claimed in my copending application Serial No. 227,599, filed August30, 1938, which issued Dec. 29, 1942 as Patent No. 2,306,776.

The refined products of my invention possess very little, if any, of theobjectionable taste and odor characteristic of the materials from whichthey are obtainedghence these products are eminently suitable for avariety of purposes and find particular application in the preparationof vitamin products for human consumption. Furthermore, extensive testshave indicated that the products of my invention have substantiallylower peroxide numbers than those of the original vitamin-containingmaterials; this factor is of great importance since vitamin-containingmaterials having low peroxide numbers are much more stable than thosehaving high peroxide numbers. Also the vitamin-bearing material isprotected against oxidative changes by the natural antioxidants whichare added to said material by the addition of the antioxidant fraction.Thus it will be evident that my invention not only improves the tasteand odor of the fat-soluble vitamincontaining materials, but alsoimproves their stability.

For a full understanding of the nature and objects of the invention,reference should be had to the following examples which are given merelyto further illustrate the invention and are not to be construed in alimiting sense, allparts given being by weight.

EXAMPLE I 5 parts of an antioxidant fraction obtained by treating crudewheat germ oil with isopropanol were added to parts of shark liver oilhaving a fishy taste and odor. The mixture was heated at 125 C. for 5minutes under reduced pressure in the presence of nitrogen gas. Acompletely odorless, bland product having the same vitamin potency andsubstantially the same color as the un treated material was obtained.

EXAMPLE II A shark liver oil having a fishy taste and odor was treatedas in Example I except that it was heated at C. instead of at C. Theresulting product was odorless and had a pleasant taste, and the vitaminpotency and color were um changed.

EXAMPLE III A substantially phosphatide-free antioxidant fraction wasprepared from crude corn germ oil by treating said oil with isopropanolas described hereinabove, adding the fraction obtained by theisopropanol treatment to suficient acetone to produce a 10% solution,cooling the acetone solution to about -18 0., and removing the fractioninsoluble at that temperature. The residue obtained on removing theactone from the acetonesoluble fraction'was a highly active antioxidantmaterial substantially free of phosphatides.

5 parts of this substantially phosphatide-free fraction were added to 95parts of shark liver oil having a fishy taste and odor, and the mixtureheated to a temperature of about C, under reduced pressure in thepresence of nitrogen gas. The resulting product was devoid of fishiness,the vitamin potency of the oil was unchanged, and the color of the oilwas substantially the same as that of the original material.

EXAMPLE IV A shark liver oil having a fishy taste and odor was treatedas in Example III except that the substantially phosphatide-freeantioxidant iratetion was prepared from crude soybean oil instead offrom crude corn germ oil. The resulting product was odorless and had apleasant taste, and the vitamin potency and color were unchanged.

The relative stability of the untreated oils and of the treated oils wasdetermined by carrying out stability tests under accelerated conditions.In these tests the oils were maintained at a constant temperature of34.5 C. in the presence oi air for a number of days and the percentageof vitamin A destroyed then determined. The results of these tests aregiven in Table I.

Table I Percent vitamin A destroyed in Sample 6 days 14 days 27 days Asample of the untreated oil used for 1 Examples I and II 5. 8 47. 4 Thetreated oil of Example I 0. 0 22. 3 The treated oil of Example II 0.023. 5 A sample of the untreated oil used for Examples III and IV 34.076. 6 The treated oil of Example III 1.4 19. 2 .i The treated oil oiExample IV 0.5 22. 4

It will be evident from the above description that my invention providesa new and effective method of preparing substantially odorless andtasteless fat-soluble vitamin-containing materials relatively stable tooxidative changes from fat-soluble vitamin-containing materials havingobjectionable tastes and odors. My invention will, therefore, be ofgreat interest to those engaged in the preparation of vitamincompositions, particularly for human and animal consumption. primarilydirected to the refining of fat-soluble vitamin-containing materials, itis also applicable tothe refining of any edible oil or fat having anobjectionable taste and odor.

Since certain changes in carrying out the above process and certainmodifications in the compositions which embody the invention may be madewithout departing from its scope, it is intended that all mattercontained in the above description shall be interpreted as illustrativeand not in a limiting sense.

Thisapplication is a continuation-in-part of my copending applicationsSerial No. 351,909, filed August 8, 1940, and Serial No. 397,547, filedJune 11, 1941.

Having described my invention, what I claim as new and desire to secureby Letters Patent, is:

1. A process of removing objectionable tastes and odors from fat-solublevitamin-containing materials and for protecting said material againstoxidative changes, which comprises mixing a fatsolublevitamin-containing material selected from the group consisting of fishoils, fish liver oils and concentrates thereof with a naturalantioxidant concentrate prepared by contacting a naturalantioxidant-containing material selected from the group consisting ofvegetable oils and vegetable oil-bearing solids, at a temperature aboveroom temperature with a solvent selected from the group consisting ofaliphatic and alicyclic monohydroxy alcohols containing from 3 to 6carbon atoms, esters formed by the reaction of aliphatic and alicyclicalcohols with aliphatic monocarboxylic acids, said esters containing notmore than 8 carbon atoms, aliphatic and alicyclic aldehydes containingnot more than 6 carbon atoms and aliphatic ketones containing not morethan 6 carbon atoms, cooling the mass to a temperature within the rangeof C. to -70 C. whereby layers are formed, separating the solvent layerfrom the insoluble residue, and removing the extracted naturalantioxidant concentrate from the solvent; heating the mixture underreduced pressure at a temperature between about 60 C. and about 200 C.for a period of' time suificient to remove the objectionable tastes andodors from said vitamin-containing material.

2. A process of removing objectionable tastes and odors from fat-solublevitamin-containing tnaterials and for protecting said material againstxidative changes, which comprises mixing a fat solublevitamin-containing material selected from the group consisting of fishoils, fish liver oiis and concentrates thereof with a naturalartioxidant'concentrate prepared by contactim. a

natural antioxidant-containing material sel *ted Furthermore, while myinvention is 7 temperature within the range of 0 C. to C. whereby layersare formed, separating the solvent layer from the insoluble residue, andremoving the extracted natural antioxidant concentrate from the solvent;heating the mixture in an inert gas atmosphere under reduced pressure ata temperature between about 60 C. and about 200 C. for a period of timesufiicient to remove the objectionable tastes and odors from saidvitamin-containing material.

3. A process of removing objectionable tastes and odors from fat-solublevitamin-containing materials and for protecting said material againstoxidative changes, which comprises mixing a. fatsolublevitamin-containing material selected from the group consisting of fishoils, fish liver oils and concentrates thereof with a naturalantioxidant concentrate prepared by contacting a naturalantioxidant-containing material selected from the group consisting ofvegetable oils and vegetable oil-bearing solids, at a temperature aboveroom temperature with a solvent selected from the group consisting ofaliphatic and alicyclic monohydroxy alcohols containing from 3 to 6carbon atoms, esters formed by the reaction of aliphatic and alicyclicalcohols with aliphatic monocarboxylic acids, said esters containing notmore than 8 carbon atoms, aliphatic and alloyclic aldehydes containingnot more than 6 carbon atoms and aliphatic ketones containing not morethan 6 carbon atoms, cooling the mass to-a' temperature within the rangeof 0 C. to 70 C. whereby layers are formed, separating the solvent layerfrom the insoluble residue, and removing the extracted naturalantioxidant concentrate from the solvent; heating the .:zixture underreduced pressure at a temperature between about C. and about C. for aperiod of time suflicient to remove the objectionable tastes and odorsfrom said vitamin-containing material.

4. A process of removing objectionable tastes and odors from fat-solublevitamin-containing materials and for protecting said material againstoxidative changes, which comprises mixing a fatsolublevitamin-containing material selected from the group consisting of fishoils, fish liver oils,

and concentrates thereof with a natural antioxidant concentrate preparedby contacting a natural antioxidant-containing material selected fromthe group consisting of vegetable oils and vegetable oil-bearing solids,at a temperature above room temperature with a solvent selected from thegroup consisting of aliphatic and allcyclic monohydroxy alcoholscontaining from 3 to 6 carbon atoms, esters formed by the reaction ofaliphatic and alicyclic alcohols with aliphatic monocarboxy c acids,said esters containing not more than carbon atoms, aliphatic andalicyclic aldehydes containing not more than 6 carbon atoms andaliphatic ketones containing not more than 6 carbon atoms, cooling themass-to a temperature within the range of 0 C. to 70 C.

whereby layers are formed, separating the solvent layer from theinsoluble residue, and removing the extracted natural antioxidantconcentrate from the solvent; heating the mixture in an inert gasatmosphere under reduced pressure at a temperature between about 100 C.and about 130 C. for a period of time sufilcient to remove theobjectionable tastes and odors from said vitamin-containing material.

5. A process of removing objectionable tastes and odors from fat-solublevitaininicontaining materials and-for protecting said material againstoxidative changes, which comprises mixing a fatsolublevitamin-containing material selected fromthe group consisting of fishoils, fish liveroils and concentrates thereof with a natural antioxidantconcentrate prepared by contacting a natural antioxidant-containingmaterial selected from the group consisting of vegetable oils andvegetable oil-bearing solids, at a temperature above room temperaturewith isopropanol, cooling the mass to a temperature within the range ofC. to 70 C. whereby layers are formed, separating the isopropanol layerfrom the insoluble residue, and removing the extracted naturalantioxidant concentrate from the isopropanol; heating the mixture underreduced pressure at a temperature between about 60 C. and about 200 C.for a period of time sufficient to remove theobjectionable tastes andodors from said vitamin-containing material.

6. A process of removing objectionable tastes and odors from fat-solublevitamin-containing materials and for protecting said material againstoxidative changes, which comprises mixing a fatsolublevitamin-containing material selected from the group consisting of fishoils, fish liver oils and concentrates thereof with a naturalantioxidant concentrate prepared by contacting a naturalantioxidant-containing wheat germ oil, at a temperature above roomtemperature with a solvent selected from the group consisting ofaliphatic and alicyclic monohyroxy alcohols containing from 3 to 6carbon atoms, esters formed by the reaction of aliphatic and alicyclicalcohols with aliphatic monocarboxylic acids, said esters containing notmore than 8 carbon atoms, aliphatic and alicyclic aldehydes-containingnot more than 6 carbon atoms and aliphatic ketones containing not morethan 6 carbon atoms, cooling the mass to a temperature within the rangeof 0 C. to 70 C. whereby layers are formed, separating the solvent layerfrom the insoluble residue, and removing the extracted natural antioxidant concentrate from the solvent; heating the mixture under reducedpressure at a temperature between about 60 C. and about 200 C. for aperiod of time sufiicient to remove the objectionable tastes and odorsfrom said vitamin-containing material,

'7. Av process of removing objectionable taste and odors fromfat-soluble vitamin-containing materials and for protecting saidmaterial against oxidative changes, which comprises mixing a fatsolublevitamin-containing material selected, from the group consisting of fishoils, fish liver oils and concentrates thereof with a naturalantioxidant concentrate prepared by contacting a naturalantioxidant-containing corn germ oil, at a temperature above roomtemperature with a solvent selected from the group consisting ofaliphatic and alicyclic monohydroxy alcohols containing from 3 to 6carbon atoms, esters formed by the reaction of aliphatic and alicyclicalcohols with aliphatic monocarboxylic acids, said esters containing notmore than 8 carbon atoms, aliphatic .and alicyclic aldehydes containingnot more than 6 carbon atoms and aliphatic ketones containing not morethan 6 carbon atoms, cooling the mass to a temperature within the rangeof. 0 C. to 70 C. whereby layers are formed, separating the solventlayer from] the insoluble residue, and removing the extracted naturalantioxidant concentrate from the solvent; heating the mixture underreduced pressure at a temperature between about 60 C. and about 200 C.for aperiod of time sufficient to remove the objectionable tastes andodors from said vitamincontaining material.

8. A process of removing objectionable tastes and odors from fat-solublevitamin-containing materials and for protecting said material againstoxidative changes, which comprises mixing a fatsolublevitamin-containing material selected froln the group consisting of fishoils, fish liver oils and concentrates thereof "with a naturalantioxidant concentrate prepared by contacting a naturalantioxidant-containing soybean oil, at a temperature above roomtemperature with a solvent selected from the group consisting ofaliphatic and alicyclic monohydroxy alcohols containing from 3 to 6carbon atoms; esters formed by the reaction of aliphatic and alicyclicalcohols with aliphatic monocarboxylic acids, said esters containing notmore than 8 carbon atoms, aliphatic and alicyclic aldehydes containingnot more than 6 carbon atoms and aliphatic ketones containing not morethan 6 carbon atoms, cooling the mass to a temperature within the rangeof 0 C. to C. whereby layers are formed, separating the solvent layerfrom the insoluble residue, and removing the extracted naturalantioxidant concentrate from the solvent; heating the mixture underreduced pressureat a temperature between about 60 C. and about 200 C.for a period of time sufficient to remove the objectionable tastes andodors from said vitamincontaining material.

9. A process of removing objectionable tastes and odors from fat-solublevitamin-containing materials and for protecting said material againstoxidative changes, which comprises mixing a fatsolublevitamin-containing material selected from the group consisting of fishoils, fish liver oils and concentrates thereof with a naturalantioxidant concentrate prepared by contacting a naturalantioxidant-containing wheat germ oil, at a temperature above roomtemperature with isopropanol, cooling the mass to a temperature withinthe range of 0 C. to 70 C. whereby layers are formed, separating thesolvent layer from the insoluble residue, and removing the extractednatural antioxidant concentrate from the solvent; heating the mixtureunder reduced pressure at a temperature between about C. and about C.for a period of time sufiicient to remove the objectionable tastes andodors from said vitamin-containing material.

10. A process of removing objectionable tastes.

"from the insoluble residue, and removing the extracted naturalantioxidant concentrate from the solvent; heating the mixture underreduced pressure at a temperature between about 100 C. and about 130 C.for a period of time sufiicient to remove the objectionable tastes andodors from said vitamin-containing material.

11. A process of removing objectionable tastes and odors fromfat-soluble vitamin-containing materials and for protecting saidmaterial against oxidative changes, which comprises mixing a fatsolublevitamin-containing material selected from the group consisting of fishoils, fish liver oils and concentrates thereof with a naturalantioxidant concentrate prepared by contacting a naturalantioxidant-containing soybean oil, at a temperature above roomtemperature with isopropanoi, cooling the mass to a temperature withinthe range of 0 C. to -'70 C. whereby layers are formed, separating thesolvent layer from the insoluble residue, and removing the extractednatural antioxidant concentrate from the solvent; heating the mixtureunder reduced pressure at a temperature between about 100 C. and about130 C. for a period of time sufficient to remove the objectionabletastes and odors from said vitamin-containing material.

' LORAN '0. BUXTON.

